Jd. Hamill, ALTERATIONS IN AUXIN AND CYTOKININ METABOLISM OF HIGHER-PLANTS DUE TOEXPRESSION OF SPECIFIC GENES FROM PATHOGENIC BACTERIA - A REVIEW, Australian journal of plant physiology, 20(4-5), 1993, pp. 405-423
This review deals with the physiological and morphological effects of
altering the auxin/cytokinin balance in transgenic plants by expressin
g specific genes from pathogenic bacteria. Genes which have been used
to alter auxin levels or sensitivity in transgenic plants include the
iaaM/iaaH genes from Agrobacterium tumefaciens and A. rhizogenes; gene
5 and possibly gene 6b from A. tumefaciens; the rol B and possibly th
e rol A gene from A. rhizogenes and the iaaL gene from Pseudomonas syr
ingae subsp. savastanoi (P. savastanoi). Genes which have been used to
alter cytokinin levels in transgenic plants include the ipt gene from
A. tumefaciens and the rol C gene from A. rhizogenes. A variety of bi
ochemical mechanisms have been identified which result in alterations
to phytohormone levels following expression of these genes in transgen
ic plants. Many of the effects on plant development are consistent wit
h observations made following exogenous auxin and/or cytokinin applica
tion to plant tissues, and the availability of these genes offers a ne
w approach to the study of plant physiology using transformation metho
dology.